This invention relates to portable electrical devices powered by batteries, and in particular the invention is concerned with a battery pack for such a device, and a convenient system for recharging the battery pack while still allowing the portable electrical device to be used in the field.
Many portable computers and other portable electrical devices have removable, rechargeable battery packs which contain a number of cells. In order to charge one of these battery packs, one can either charge the battery while it is in the computer or electrical device, or one can remove the battery pack and connect it into an external battery charger made specifically for the battery pack.
Charging the battery while it is in the electrical device is the easier method. This is done simply by using the AC-DC converter and input power plug normally sold with the device and used for powering the device without the battery, such as in an office with wall current available.
However, this charging method is limited in that one battery cannot be charged while another is taken into the field with the computer or other electrical device.
An external battery charger designed for the specific battery pack will allow the charging of one or more batteries at the operator's home or office, while another is taken into the field in the computer or other device. However, this requires purchase of the separate, dedicated battery charger.